Not applicable.
1. Field of the Invention
The subject invention relates to coating apparatuses and methods of coating and, more particularly, to apparatuses and methods for applying a coating material to sheet-like materials in a cascading fashion.
Over the years, a variety of different apparatuses and methods have been developed for applying coating materials, paint, cleaning solutions, etc. to sheet materials. U.S. Pat. No. 3,069,285 to Viscardi and U.S. Pat. No. 3,529,992 to Sinclair disclose various apparatuses and methods for applying color mediums to sheet-like materials. U.S. Pat. No. 3,155,530 discloses apparatus and methods for coating a strip of steel by passing the strip through a coating pot that contains a coating material.
Still other methods and apparatuses have evolved for applying coating or cleaning materials to continuous strip materials. A common theme generally employed in such methods is that the strip material is supported horizontally, such that the plane of the top surface of the strip is oriented parallel to the horizon, and the coating is applied to the top surface by spraying, applicator rolls, etc. Or, the horizontally-oriented strip may be dipped and moved vertically upward from the plane of the horizon. In those applications wherein a liquid coating material is employed, squeegee rollers and/or wipers may be employed to remove excess coating from the sheet material. If such squeegees and/or wipers inadvertently become contaminated during the coating process, such contamination can be transferred to the coated surface and result in imperfections in the coating. In addition, such devices must typically be precisely adjusted to avoid unacceptable non-uniformities in the coating.
Another method that has been employed to remove excess coating material from sheet material involves the use of air knives that blow a stream of air onto the coated sheet material as it passes thereunder. The stream of air blows the excess material in a predetermined direction until it is blown off of the strip. In applications wherein the strip is supported horizontally, the air knives blow the excess coating material back onto the excess coating material that remains on the strip. Such arrangement tends to increase the overall resistance between the excess material and the strip that can lead to undesirable non-uniform coating thickness. Moreover, because the strip is oriented horizontally, it is more susceptible to collecting dirt, dust and debris which can lead to undesirable coating imperfections. Those of ordinary skill in the art will of course appreciate that the above-mentioned problems are often encountered in all types of applications wherein a material is applied to a horizontally oriented strip of material regardless of whether the applied material is a cleaning solvent, paint, powdered coating material, metallic coating material, etc.
Thus, there is a need for a apparatuses and methods for applying a coating material, solvent, paint, cleaning material etc. to a sheet-like material that does not have the shortcomings of prior coating methods.
There is a further need for an apparatus that can apply a coating material to a sheet-like material in a more efficient manner.
There is still another need for an apparatus for applying a coating material to a sheet-like material that does not encounter the dirt and debris problems often encountered with prior coating methods.
Another need exists for a coating system for sheet-like material wherein excess coating material can be reapplied to the sheet-like material.
Yet another need exists for a coating system wherein different types of coatings can be easily applied to the sheet-like material.
Another need exists for a method for applying a coating material to a continuously moving strip of material having planar surfaces without the need to support the planar surfaces as the coating material is applied thereto.
There is a further need for a coating process that has the above-mentioned attributes that can be used to apply a variety of different heated coatings to a strip of material.
Another need exists for an apparatus for applying a coating material to a strip of steel that requires minimal downtime to change between different types of coating materials.
In accordance with a particularly preferred form of the present invention, there is provided an apparatus for applying a first material to a moving second material that has at least two edges. In a preferred form, the apparatus includes at least one supporter for supporting the second material in a substantially non-horizontal orientation. The apparatus also includes at least one applicator for applying the first material to the second material adjacent to one edge of the second material such that the first material substantially migrates across the second material towards the other edge thereof as the second material moves in a predetermined direction.
Another embodiment of the present invention comprises an apparatus for applying a liquid coating material to a moving sheet material that has a first edge surface and a second edge surface. The apparatus preferably comprises at least one support member that contacts at least portions of the first edge surface of the moving sheet material and supports the moving sheet material in a non-horizontal orientation. The apparatus also includes at least one coating applicator for applying the coating material adjacent at least a portion of the second edge of the moving sheet material such that the coating material substantially migrates across the sheet material towards the first edge thereof at least under some gravitational influence.
Another embodiment of the present invention includes apparatus for applying a first material to coiled strip material. The apparatus includes a decoiler for supporting the coil of strip material and unwinding the strip material therefrom. The apparatus also includes a coiler for rewinding the strip material into another coil. In addition, the apparatus includes a coating chamber for substantially surrounding at least a portion of the strip material as it passes in a non-horizontal orientation from the decoiler to the coiler and at least one applicator oriented within the coating chamber to apply the material to the strip material adjacent to one edge of the strip material as it passes through the coating chamber. The apparatus may also include at least one wiper assembly for dispersing the material on the strip material as it passes through the coating chamber and an exhaust attached to the coating chamber for removing vapor therefrom.
The present invention may also comprise a method for applying a first material to a second material that has at least two edges. In a preferred form, the method comprises supporting the second material on one edge thereof in a non-horizontal orientation and applying the first material to the second material adjacent another edge of the second material such that at least some of the first material migrates toward the supported edge of the second material under a gravitational influence.
Another embodiment of the present invention comprises a method for applying a material to coiled strip material. The method may include unwinding the coiled strip material and supporting the unwound strip material on one edge thereof in a non-horizontal orientation. In addition, the method includes driving the supported unwound strip material in a predetermined direction while it is in the non-horizontal orientation. The method may also include applying the material to the driven strip material adjacent another edge thereof such that the applied material migrates across said strip material towards the supported edge thereof at least partially under a gravitational influence and rewinding the strip material into another coil after the first material has been applied thereto.
It is a feature of the present invention to provide an apparatus and method for applying a coating material such as molten zinc and other materials to a strip of annealed steel that results in a more efficient application of the zinc on the steel.
It is another feature of the present invention to provide an apparatus and method with the above-mentioned attributes that also results in increased versatility in the range of the thickness of coating that may be applied to the steel.
It is another feature of the present invention to provide apparatus and methods with the above-mentioned attributes that also facilities reduced downtime associated with changing between coatings.
Still another feature of the present invention is to provide steel trip treatment apparatuses and methods with the above-mentioned attributes that can employ small coating reservoirs, which lead to reduced system manufacturing and operating costs.
Another feature of the present invention is to provide apparatuses and methods for applying a coating agent, cleaning agent, paint, etc. to a material.
Still another feature of the present invention is to provide apparatuses and methods for applying a first material to a second material that allow for the filtering of impurities from the first material and thereby the reduction in defects in the application of the first material to the second material resulting from dirt and debris.
Accordingly, the present invention provides solutions to the shortcomings of prior coating methods. Those of ordinary skill in the art will readily appreciate, however, that these and other details, features and advantages will become further apparent as the following detailed description of the preferred embodiments proceeds.